Radiation anode target systems and methods

ABSTRACT

Presented systems and methods facilitate efficient and effective generation and delivery of radiation. A radiation generation system can comprise: a particle beam gun, a high energy dissipation anode target (HEDAT); and a liquid anode control component. In some embodiments, the particle beam gun generates an electron beam. The HEDAT includes a solid anode portion (HEDAT-SAP) and a liquid anode portion (HEDAT-LAP) that are configured to receive the electron beam, absorb energy from the electron beam, generate a radiation beam, and dissipate heat. The radiation beam can include photons that can have radiation characteristics (e.g., X-ray wavelength, ionizing capability, etc.). The liquid anode control component can control a liquid anode flow to the HEDAT. The HEDAT-SAP and HEDAT-LAP can cooperatively operate in radiation generation and their configuration can be selected based upon contribution of respective HEDAT-SAP and the HEDAT-LAP characteristics to radiation generation.

RELATED APPLICATIONS

This application is a continuation claiming the benefit of and priorityto application Ser. No. 16/045,598 entitled “Radiation Anode TargetSystems and Methods”, filed on Jul. 25, 2018, which is incorporatedherein by reference.

FIELD OF THE INVENTION

The present invention relates to the field of radiation beam generationand control. In one embodiment, systems and methods facilitate fast andeffective application of radiation therapy.

BACKGROUND

Radiation beams can be utilized in a number of different applicationsand accurately applying an appropriate amount of radiation can be veryimportant. Radiation beam therapy typically includes directing aradiation beam at an area of tissue. There can be various differenttypes of radiation beams (e.g., photon, ionizing particle, etc.). Theradiation beams are typically used to stop the growth or spread of thetargeted tissue cells by killing them or degrading their cell divisionability. While radiation therapy is generally considered beneficial,there can be a number of potential side effects. The side effects caninclude unintended damage to DNA of healthy tissue cells. Theeffectiveness of radiation therapy is primarily a function of the doseor amount of ionizing radiation that is applied to cancerous cells whileavoiding impacts to healthy cells.

The amount of radiation that is applied to the tissue is typically afunction of a dose rate and time the targeted tissue is exposed to theradiation. In some implementations, the dose rate corresponds to the“current” of charged particles used to generate the radiation. Thecharged particle (e.g., proton, electron, etc.) can be directed at thetissue or can be directed at an intermediate target that producesanother fundamental or elementary particle (e.g., photons, neutrons,etc,) which are directed at the tissue. The elementary particles canhave radiation characteristics (e.g., X-ray wavelength, ionizingcapabilities, etc.). Higher dose rates usually enable shorter exposuretimes and that can have a number of benefits, including less opportunityfor extraneous events to influence the therapy, increased productivity,and greater convenience to the patient. Some conventional approacheshave attempted to increase dose rate through higher MeV values. However,developing systems and methods compatible with higher MeV values can bedifficult and problematic for conventional anode approaches. Forexample, use of higher MeV values can produce excess neutrons, whichresults in increased costs associated with measures (e.g., increasedshielding, etc.) to counteract affects of the excess neutrons.

One considerable conventional obstacle is maintaining performance (e.g.,radiation output levels, component structural integrity, etc.) whileavoiding problematic conditions (e.g., overheating, environmentalimpacts, etc.). Heat loading capabilities of traditional solid anodetargets (e.g., used in incident electron beam deceleration, used inproduction of Brehmmstralung radiation, etc.) do not typically provideadequate heat dissipation at high energy densities (e.g., power into thetarget) and the targets begin to melt and lose performancecharacteristics. Conventional improvements to a solid anode target(e.g., a rotating solid anode target, etc.) are usually difficult toemploy as transmission targets and do not typically offer muchimprovement in heat dissipation. Traditional approaches using freeflowing liquid anode jet streams can result in reduced and inconsistentradiation generation.

SUMMARY

Presented systems and methods facilitate efficient and effectivegeneration and delivery of radiation. In some embodiments, a radiationgeneration system comprises: a particle beam gun, a high energydissipation anode target (HEDAT); and a liquid anode control component.The radiation system can be a therapeutic radiation system. In oneexemplary embodiment, the particle beam gun generates an electron beam.The HEDAT includes a solid anode portion (HEDAT-SAP) and a liquid anodeportion (HEDAT-LAP) configured to receive the electron beam, absorbenergy from the electron beam, generate a radiation beam, and dissipateheat. The radiation beam can include photons that can have radiationcharacteristics (e.g., X-ray wavelength, ionizing capabilities, etc.).The liquid anode control component is configured to control a flow of aliquid anode to the HEDAT.

The HEDAT-SAP and HEDAT-LAP cooperatively operate in radiationgeneration and control. The configuration of the HEDAT-SAP and theHEDAT-LAP can be selected based upon contributions of respectiveHEDAT-SAP and HEDAT-LAP characteristics to radiation generation and heatdissipation. The received electron beam can have an energycharacteristic equal to or greater than 1 MeV. The HEDAT includes solidsurfaces that confine the flow of the liquid anode through the HEDAT. Asurface that confines the flow of the liquid anode through the HEDAT canalso be a surface of the solid anode target. The liquid anode controlcomponent can control pressure and temperature of the liquid anode. Theliquid anode can absorb heat from electron beam collisions within theliquid anode and heat via conduction from the solid energy anode. Insome embodiments, the HEDAT can include a surface that forms a wall of achannel configured to confine a flow of a liquid anode. The HEDAT-SAPcan be made from a material that has at least one of the followingcharacteristics: low density, low atomic number, high heat capacity,high thermal conductivity, high melting point, high Yield strength athigh temperatures, high electrical conductivity, Rad hard, resistant tocorrosive characteristics of the HEDAT-LAP, and so on. The HEDAT-SAP andHEDAT-LAP cooperatively operate to enhance energy compatibilitycharacteristics of the HEDAT. The liquid anode can include a materialthat has at least one of the following characteristics: high heatcapacity, low melting point, high thermal conductivity, high boilingpoint, high density, high atomic number, low viscosity, non-corrosive,and so on.

In some embodiments, a radiation method comprises: receiving an electronbeam at a high energy dissipation anode target (HEDAT); generatingradiation in a solid anode portion (HEDAT-SAP) and a liquid anodeportion (HEDAT-LAP) of the HEDAT; dissipating heat; and controlling aflow of liquid anode material to and from the HEDAT-LAP. The radiationgeneration can include absorbing energy resulting from electron beamcollisions in the HEDAT-SAP and the HEDAT-LAP. The heat resulting fromenergy absorption in the solid anode target and a liquid anode target isdissipated. In one embodiment, the HEDAT-LAP dissipates heat generatedinternally by particle collisions within the HEDAT-LAP and also heatresulting from conduction transfer from the HEDAT-SAP. Dissipating theheat includes flowing cool liquid anode material into the HEDAT and warmliquid anode material out of the HEDAT (e.g., the liquid anode leavingthe HEDAT is warmer than the liquid anode entering the HEDAT). Theradiation method can also include forwarding a resulting generatedradiation beam to a treatment target.

In some embodiments, a radiation therapy system comprises: a beamgeneration system that generates and transports a radiation beam inaccordance with a prescribed treatment plan, and a control componentthat receives information on radiation delivery associated with theradiation beam and directs execution of a prescribed treatment plan. Theradiation beam can include elementary particles that have radiationcharacteristics. In some embodiments, a beam generation systemcomprises: a particle beam gun, a high energy dissipation anode target(HEDAT); and a liquid anode control component. The beam generationsystem can include a linear accelerator and components that direct anelementary particle beam in a direction toward and into a target. Thetarget may be mounted on or be a part of a fixed, rotating, or movablegantry so that it can be moved relative to a supporting device thatsupports the patient.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings together with the description are incorporatedin and form a part of this specification. They illustrate exemplaryembodiments and explain exemplary principles of the disclosure. They arenot intended to limit the present invention to the particularembodiments illustrated therein. The drawings are not to scale unlessotherwise specifically indicated

FIG. 1 is a block diagram of an exemplary radiation system in accordancewith one embodiment.

FIG. 2 is a block diagram of an exemplary HEDAT in accordance with oneembodiment.

FIG. 3 is a block diagram of an exemplary HEDAT and system components inaccordance with one embodiment.

FIG. 4 is a block diagram comparison of radiation emitting collisions inan exemplary HEDAT and conventional solid anode target in accordancewith one embodiment.

FIG. 5 is a block diagram of exemplary heat transfer in accordance withone embodiment

FIG. 6 is a block diagram of a different exemplary HEDAT-LAP flow systemin accordance with one embodiment.

FIG. 7 is a table of liquid anode elements in accordance with oneembodiment.

FIG. 8 is a block diagram of an exemplary HEDAT in accordance with oneembodiment.

FIG. 9 is a block diagram of an exemplary different side view of a HEDATin accordance with one embodiment.

FIG. 10 is a block diagram of another exemplary HEDAT-LAP configurationin accordance with one embodiment.

FIG. 11 is a block diagram of an exemplary HEDAT with auxiliarycomponents in accordance with one embodiment.

FIG. 12 is a block diagram of an exemplary particle beam generationmethod in accordance with one embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the illustrated, exemplaryembodiments in the accompanying drawings. While the invention will bedescribed in conjunction with the exemplary embodiments, it will beunderstood that they are not intended to limit the invention to theseembodiments. On the contrary, the invention is intended to coveralternatives, modifications and equivalents, which may be includedwithin the spirit and scope of the invention as defined by the appendedclaims. Furthermore, in the following detailed description of thepresent invention, numerous specific details are set forth in order toprovide a thorough understanding of the present invention. However, itwill be obvious to one ordinarily skilled in the art that the presentinvention may be practiced without these specific details. In otherinstances, well known methods, procedures, components, and circuits havenot been described in detail as not to unnecessarily obscure aspects ofthe current invention.

Presented systems and methods facilitate efficient and effectiveradiation generation and control. In one embodiment, a high energydissipation target is capable of operating with high energy beams. Thehigh energy dissipation target can operate as an anode to produceradiation. In one exemplary implementation, a high energy dissipationanode target (HEDAT) includes a solid anode portion (HEDAT-SAP) and aliquid anode portion (HEDAT-LAP). The HEDAT-SAP and HEDAT-LAP can beconfigured to collaboratively contribute to radiation emission, energyabsorption, heat dissipation, and so on. A HEDAT-LAP can enableutilization of a HEDAT-SAP with certain configuration characteristics(e.g., heat dissipation characteristic, radiation generationcharacteristics, etc.), and vice versa. The HEDAT-SAP and HEDAT-LAPcooperatively operate to enhance energy compatibility characteristics ofthe HEDAT. In one embodiment, a HEDAT is capable of receiving a highenergy input (e.g., greater than 1 MeV) and efficiently generatingradiation while maintaining system integrity (e.g., providing accurateradiation output, enabling output fidelity, avoiding overheating, etc.).

FIG. 1 is a block diagram of an exemplary radiation therapy system 100.Radiation therapy system 100 includes an accelerator and beam transportsystem 110, multi-leaf collimator (MLC) 120, control system 150, andsupporting device 190. In one exemplary implementation, the acceleratorand beam transport system 110 generates and transports a radiation beamof elementary particles (e.g., photons, etc.) that have radiationcharacteristics. In one embodiment, a plurality of elementary particlestravel in substantially the same direction and are included in a beam.The beam of elementary particles can form a radiation beam. In oneexemplary implementation, the radiation beam includes X-rays.

Accelerator and beam transport system 110 includes gun subsystem 111,drift tube 115, and high energy dissipation anode target (HEDAT) 117.Gun subsystem 111 generates a particle beam (e.g., electron beam, etc.).In one embodiment, gun subsystem 111 is compatible with timing controlof beam generation operations in a microwave frequency range.Accelerator and beam transport system 110 can include a particleaccelerator that accelerates a particle generated by the gun subsystem111.

The system is compatible with a variety of accelerators (e.g., acontinuous wave beam accelerator, betatron, an isochronous cyclotron, apulsed accelerator, a synchrocyclotron, a synchrotron, etc.). In oneembodiment, accelerator and beam transport system 110 includes a linearaccelerator (LINAC). In one exemplary implementation, the accelerator iscapable of relatively continuous wave output and extracts particles witha specified energy. The LINAC drift tube 115 allows electrons emitted bythe gun-subsystem 111 to travel to the HEDAT 117. In one embodiment, theelectrons are decelerated by a HEDAT used in production ofBrehmmstralung radiation at high energies (e.g., 1-25 MeV, etc.).

In one embodiment, the gun subsystem 111 generates a primary electronparticle beam that is used to create a secondary photon radiation beam.A primary electron particle beam generator may be configured tocorrelate the time of secondary photon emission with the primaryelectron particle beam generation (e.g., to further improvesignal-to-noise ratio, etc.). HEDAT 117 can receive high energy input(e.g., greater then 1 MeV, etc.) and generate relatively high quantityradiation while maintaining system integrity, including dissipatingexcess heat. In one exemplary implementation, the HEDAT generatesradiation in the form of X-rays. Additional description of high energyanodes is presented in later portions of this specification.

The accelerator and beam transport system 110 can include various othercomponents (e.g., dipole magnets, bending magnets, etc.) that direct(e.g., bend, steer, guide, etc.) a beam through the system in adirection toward and into the MLC 120. The accelerator and beamtransport system 110 may also include components that are used to adjustthe beam energy entering the MLC 120.

In one embodiment, MLC 120 includes components that control a beamshape. In one exemplary implementation, a MLC leaf can be independentlyadjusted (e.g., moved back-and-forth, etc.) to dynamically shape anaperture through which a beam can pass. The adjustments can be directedby control system 150. The aperture can block or not block portions ofthe beam and thereby control beam shape and exposure time. The beam canbe considered a relatively well-defined beam. The MLC 120 can be used toaim the beam toward various locations within an object (e.g., a patient,target tissue, etc.). In one embodiment, the MLC 120 controls aradiation beam in “X and Y directions” to scan a target tissue volume.

The object (e.g., a target tissue volume in a patient, etc.) can belocated on the supporting device 190 (e.g., a chair, couch, bench,table, etc.) in a treatment room. In one embodiment, the supportingdevice is moveable. The MLC 120 may be mounted on or a part of a fixed,rotating or movable gantry (not shown) so that it can be moved relativeto the supporting device 190. The accelerator and beam transport system110 can also be mounted on or be a part of the gantry. In anotherembodiment, the beam generation system is separate from the gantry. Inone exemplary implementation, a separate beam generation system is incommunication with the gantry.

In one embodiment, control system 150 receives and directs execution ofa prescribed treatment plan. In one exemplary implementation, thecontrol system 150 includes a computer system having a processor,memory, and user interface components (e.g. a keyboard, a mouse, adisplay, etc.). The control system 150 can control parameters andoperations of the accelerator and beam transport system 110, MLC 120,and supporting device 190, including parameters such as the energy,intensity, direction, size, and shape of the beam. The control system150 can receive data regarding operation of the system 100 and controlthe components according to data it receives. The data can be includedin the prescribed treatment plan. In one embodiment, the control system150 receives information and analyzes the performance and treatmentbeing provided by radiation therapy system 100. In one embodiment, thecontrol system 150 can direct adjustments to the radiation therapysystem 100 based upon the analysis of dose and dose rate.

It is appreciated that a high energy dissipation anode target (HEDAT)can be compatible with a variety of radiation treatment approaches. AHEDAT can be utilized for high dose rate treatments. In one embodiment,a HEDAT is used to deliver radiation therapy capable of dose rates thatcorrespond to time intervals of frozen movement or no movement in atreatment target. In one exemplary implementation, a radiation treatmentdose rate is compatible with delivery of radiation to a treatment targetin a chest area in a time interval corresponding to no movement in thechest area due to inhaling or exhaling a breath (e.g. no movement due toa lung expanding, contracting, etc.).

Some treatment or therapy approaches include ultra-high dose ratetreatment or modality referred to as FLASH radiotherapy. Therapeuticwindows associated with FLASH therapy often enable reduced normal tissuetoxicity while maintaining cancerous tissue tumor control. In oneembodiment, a HEDAT is used to deliver FLASH radiation therapy. In oneexemplary implementation, the FLASH radiotherapy dose rate can be atleast 4 Gray (Gy) in less than one second and as much as 20 Gy or 40 Gyin less than a second. The FLASH radiotherapy dose rate can be more than40 Gy in less than one second. The radiation therapy systems and methodscan also be compatible with multiple field treatment approaches in whichdifferent fields are associated with a particular treatment trajectoryand a dose per field that is a portion or fraction of a total dosedelivery.

FIG. 2 is a block diagram of an exemplary HEDAT 200 in accordance withone embodiment. HEDAT 200 includes solid anode portion (HEDAT-SAP) 210and liquid anode portion (HEDAT-LAP) 220. HEDAT-LAP 220 includes walls221, 222, 223, and 224. Walls 221 and 224 include access regions 227 and229. A liquid anode can flow through access regions 227 and 229. It isappreciated that other walls or surfaces of a HEDAT-LAP can also includeaccess regions. In one exemplary implementation, the walls 221, 222,223, and 224 can form a channel to contain and control the flow theliquid anode. A HEDAT-SAP can form a wall of a HEDAP-LAP. In oneembodiment, HEDAT-SAP 210 can serve as wall 222 of HEDAT-LAP 220. TheHEDAT-SAP 210 and HEDAT-LAP 220 cooperatively operate in radiationgeneration to augment or increase the compatibility characteristics ofthe HEDAT with high energy input. The HEDAT-SAP 220 and HEDAT-LAP 210can be configured to collaboratively contribute to radiation emission,energy absorption, heat dissipation, and so on.

FIG. 3 is a block diagram of an exemplary high energy radiationgeneration system 300. High energy radiation generation system 300includes gun sub-system 321, LINAC drift tube 322, and HEDAT 330. In oneembodiment, gun sub-system 321, LINAC drift tube 322, and HEDAT 330 aresimilar to gun subsystem 111, LINAC drift tube 115, and high energyanode 117. In one exemplary implementation, gun subsystem 321 generatesan electron beam that is conveyed through LINAC drift tube 322 to HEDAT330. HEDAT 330 includes HEDAT-SAP 331 and HEDAT-LAP 333. As theelectrons from the electron beam travel through the HEDAT 330 there arecollisions with components of the HEDAT-SAP 331 and HEDAT-LAP 333 andthe collisions result in generation or emission of radiation. Theradiation can include elementary particles. The radiation can includephotons. The emissions can be configured in a radiation beam. Theemissions can include X-rays. In some embodiments, a liquid anode flowsfrom the liquid anode input 310 into the HEDAT-LAP 333 and out to theliquid anode output 390. The HEDAT 330 can facilitate utilization of ahigh energy input electron beam (e.g., greater than 1 MeV, etc).

In some embodiments, generation of the radiation beam is the result ofelectron collisions with elementary particles in both the HEDAT-SAP andthe HEDAT-LAP, unlike a typical conventional system configured with justone type of anode material. The liquid anode portion contribution toboth radiation generation and heat dissipation can enable utilization ofhigher energy input than a typical traditional approach that reliesentirely on a solid anode. FIG. 4 is a block diagram comparison of anexemplary conventional solid anode target 410 and an exemplary HEDAT 420in accordance with an exemplary embodiment. In a conventional solidanode target 410 all or most of the collisions and resulting heatgeneration occur within the solid anode target 410. The solid anodetarget 410 has relatively little heat dissipation capability (e.g., isbasically limited to non-ionizing thermal radiation through the externalsurface and/or conduction etc.). The bulk of the heat is trapped withinthe solid anode target 410. The longer the electron beam 471 is applied,the greater the heat build up, eventually reaching a collapse or meltingpoint.

In exemplary HEDAT 420, the collisions occur in both the HEDAT-SAP 421and HEDAT-LAP 422. In one exemplary implementation, the bulk of thecollisions happen in a liquid anode within the HEDAT-LAP 422. Eventhough the electron beam 491 may be applied to the HEDAT 420 for arelatively long period of time, movement of the liquid anode flowensures a given portion of the liquid anode flow is not subjected orexposed to the electron beam for a full period of time the electron beam491 is applied to the HEDAT 420. Thus, the heat does not continue tobuild up in a single given portion of the liquid anode the whole timethe electron beam 491 is applied. In some embodiments, the solid window423 also comprises a material that emits radiation and heat. In oneexemplary implementation, the solid window 423 is also considered aHEDAT solid anode portion or HEDAT-SAP of HEDAT 420. In one exemplaryembodiment, solid window 423 permits radiation from the HEDAT-SAP 421and HEDAT-LAP 422 to pass or flow through and emit from the solid window423 with negligible or little radiation generated in the solid window423. The solid window 423 is can be considered a non-anode portion ofthe HEDAT 420.

The HEDAT-SAP 421, solid window 423, and HEDAT-LAP 422 are configured sothat heat generation and dissipation avoid the melting or collapse pointin HEDAT-SAP 421 and solid window 423. It is appreciated that a numberof factors and characteristics can be included in the configurationselection of HEDAT-SAP 421, solid window 423, and HEDAT-LAP 422. In someembodiments, the HEDAT-SAP is thinner than a conventional approach solidportion that relies entirely on a solid anode for radiation generation.

In some embodiments, the location of heat generation from particlecollisions and the transfer of heat from the location of generation canimpact the configuration of the HEDAT. FIG. 5 is a block diagram of anexemplary HEDAT 500 in accordance with one embodiment. In HEDAT 500, theparticle collisions and heat generation occurs in the HEDAT-SAP 510,HEDAT-LAP 520, and solid window 530. The transfer of at least a portionof the resulting heat can occur through the removal of the heated liquidanode from the HEDAT-LAP 520 via the liquid anode flow. In someembodiments, the transfer of at least a portion of the resulting heatoccurs through convective heat transfer via the liquid anode inHEDAT-LAP 520. In one exemplary embodiment, HEDAT-SAP 510 and solidwindow 530 convey at least a portion of the heat via conduction to theliquid anode in HEDAT-LAP 520 (e.g., internally within the HEDAT 500,etc), and also externally to the environment through non-ionizingthermal radiation. It is appreciated that the HEDAT-SAP 510 and solidwindow 530 can also include other heat removal components (e.g.,radiator, coil, fan, etc.) that participate in heat transfer. In oneexemplary embodiment, the HEDAT-SAP 510 is coupled to a heat exchangecomponent 570. The heat exchange component 570 can enhance or supplementthe heat removal by the liquid anode via various additional passive andactive heat transfer mechanisms (e.g., radiator, coil, fan, etc.).

In some embodiments, molten metal is used as the liquid anode material.The liquid anode material is heated to at least the minimum meltingtemperature during idle times (e.g., an electron gun not activelygenerating an electron beam, system not generating radiation beams,etc.). When the radiation generation system is actively producingradiation beams and the liquid anode temperature increases in the HEDAT,the liquid anode material can be re-circulated and cooled down to alower temperature but still hot enough to maintain a liquid state. Insome embodiments, the molten metal liquid anode has a low meltingtemperature as reasonably or practically possible so that the flow canbe more easily maintained during system idle while limiting absolutetemperatures of the circulation system (e.g., tube walls, channel walls,etc.) during system operations.

FIG. 6 is a block diagram of an exemplary liquid anode circulationsystem 600 in accordance with one embodiment. Liquid anode circulationsystem 600 includes liquid anode control component 610, HEDAT 620,liquid anode input component 630, and liquid anode output component 640.HEDAT 620 includes HEDAT-SAP 621 and HEDAT-LAP 622. A liquid anode canflow from liquid anode control component 610 through liquid anode inputcomponent 630 to HEDAT-LAP 622. The flow can continue through HEDAT-LAP622 to liquid anode output 640 and back to liquid anode controlcomponent 610. Liquid anode control component 610 can control variouscharacteristics of the liquid anode as it leaves the liquid anodecontrol component (e.g., the temperature, flow rate, pressure, selectionof liquid anode components or elements, etc.). In some embodiments,there is a reservoir 615 of liquid anode material in the liquid anodecontrol component 610 that is pre-heated to convert the anode materialinto a liquid at the appropriate temperature. The liquid anode controlcomponent 610 can also include a cooling component or system for coolingthe returned liquid anode and also participate in maintaining thereservoir at an appropriate temperature. In some embodiments, thetemperature of the liquid is maintained at a level that does notadversely impact the liquid or solid components (e.g., does not melt thesolid component, vaporizes the anode material itself, causes too high adensity change, etc.).

The components of liquid anode circulation system 600 cooperativelyoperate to move flow of the liquid anode through the system. Liquidanode input component 630 conveys the liquid anode from liquid anodecontrol component 610 to HEDAT-LAP 622. Liquid anode output component640 conveys the liquid anode from HEDAT-LAP 622 to liquid anode controlcomponent 610. In some embodiments, liquid anode output component 640 isconsidered a cooling jacket. Liquid anode circulation system 600 caninclude various other components that participate in liquid anode flowcontrol. In some embodiments, liquid anode circulation system 600 caninclude components to control various aspects of the liquid anode,including components that control flow (e.g., pump 619, valve 631, etc),components to add or remove liquid anode from the system (e.g., accesspoint 611, drain 612, drain 623, etc.), heat transfer components toremove or add heat (e.g., component 617, heater, cooler, coil, fan,etc.), and so on. The system can also include intermediate components(e.g., 632, 641, etc.) at various locations that perform severalfunctions that impact the liquid anode (e.g., heat, pump, drain, etc.).

It is appreciated a HEDAT can have various different configurations.Some surfaces or walls of a HEDAT can be selected for radioactiveemission characteristics and other surfaces or walls (e.g. side wall,surface portion not in the electron beam path, etc.) can be selectedwith an emphasis on increased heat conductivity characteristics. In someembodiments, a surface or wall can also be selected for radiationresistance or blocking ability (e.g., to facilitate containment ofradiation from undesirable emission, etc.). In some embodiments, thesolid anode components of the HEDAT have various characteristicsincluding one or more of the following: a low atomic number, lowdensity, high heat capacity, high thermal conductivity, high meltingpoint, high boiling point, high electrical conductivity, high yieldstrength, physical properties relatively unaffected by radiation(radiation hard or Rad-hard), noncorrosive, and so on. The solid anodescan be configured with various materials (e.g., beryllium, titanium,carbon, etc.). In some embodiments, a solid anode has one or more of thefollowing characteristics: a density less than or equal to 5 g/cm3, anatomic number less than or equal to 25, a heat capacity greater than orequal to 0.03 J/gC, a thermal conductivity greater than or equal to 4W/(mK), a melting point greater than or equal to 1,000 C, a boilingpoint greater than or equal to 2000° C., yield strength greater than orequal to 200 MPa, and electric conductivity greater than or equal to 1.0E+5. In some embodiments, solid and liquid anodes avoid or minimize theinclusion of lead and cadmium. In some embodiments, a liquid anode hasone or more of the following characteristics: a density greater than orequal to 6 g/cm3, an atomic number greater than or equal to 30, a heatcapacity greater than or equal to 0.03 J/gC, a thermal conductivitygreater than or equal to 4.0 W/(mK), a melting point lower than or equalto 150° C., a boiling point greater than or equal to 2,000° C., andviscosity lower or equal to 0.02 Pa-s. FIG. 7 is a table of liquid anodeelements in accordance with one exemplary embodiment. Several candidatelow melting temperature metals and eutectics are listed in the table.

It is appreciated the configuration of HEDAT-SAP and HEDAT-LAP can becoordinated in accordance with various characteristics and objectives toachieve efficient generation of a radiation beam. In one embodiment,configuration of the HEDAT-SAP and HEDAT-LAP is selected based uponcollaborative operation and corresponding impacts. In one exemplaryimplementation, the individual and collaborative impacts of theHEDAT-SAP and HEDAT-LAP characteristics on heat generation and heatdissipation are considered in the configuration selection.

In one embodiment, a HEDAT-SAP generates less heat than a typicalconventional solid anode under exposure to similar relatively highenergy levels. The HEDAT can rely on the HEDAT-LAP producing some ormost of the radiation generation to meet desired radiation output, thusthe HEDAT-SAP can be thinner than a typical conventional solid anode. Inone exemplary implementation, the relatively high energy input particlescan penetrate the HEDAT-SAP easier than a conventional solid anode withless generation of heat. Less generation of heat means less heat has tobe dissipated by the HEDAT-SAP and the heat capacity of the HEDAT has abetter opportunity to keep up with the heat generation withoutoverheating. The liquid anode can flow though the HEDAT-LAP 1) allowingrelatively cool liquid anode to flow in, 2) participate in particlecollision and radiation generation in the HEDAT-LAP while absorbingcorresponding energy and heat generation, and 3) allowing the relativelywarm liquid anode to flow out without excessive heat build up oroverheating. The liquid anode can also assist absorb heat transferredfrom the HEDAT-SAP and include the heat in the relatively warm liquidanode to flow out without excessive heat build up or overheating.

The HEDAT-SAP can be configured to assist control of the liquid anodeflow. In some embodiments, the HEDAT-SAP is configured to restrict orconfine the liquid anode flow to a prescribed area. In some embodiments,the confinement can cause compaction or compression of the liquid anode,which in turn can contribute to increased radiation emission. Differentmaterials with different characteristics can be utilized in thedifferent components of the HEDAT. Thus, coordinated configuration ofthe HEDAT-SAP and HEDAT-LAP facilitates enhanced performance.

It is appreciated the configuration within the HEDAT-LAP can also vary.A HEDAT-LAP can be configured with multiple liquid anode channels. Insome embodiments, the liquid anode channels can offer improved fluiddynamics and/or the ability to operate at multiple energies. The liquidanode flow in the channels can be controlled (e.g., turned on, shut off,increased, decreased, etc.). Valves can be utilized to implement thecontrol. The amount of flow can be based upon the beam energy. At lowerenergies less anode material is required to stop the incident electronswhile at higher energies more anode material is required. Use of thechannels can be helpful in maintaining a flow pattern and to reduceeddies or local recirculation within the HEDAT-LAP channel or chamber.The channels can contain different anode materials that help increasethe flux while minimizing electron straggle. In one embodiment, a higherenergy channel contains a higher Z liquid anode (e.g., like Fields'metal, etc.) and a low energy channel contains lower Z liquid anode(e.g., gallium, etc.).

FIG. 8 is block diagram of exemplary HEDAT 800. HEDAT 800 includesHEDAT-SAP 810 and HEDAT-LAP 820. HEDAT-LAP 820 includes multipleHEDAT-LAP channels (e.g., 821, 822, 823, 824, etc.). The HEDAT-LAPchannels can have different configurations and characteristics. TheHEDAT-LAP channels can have the same or different liquid anode flows(e.g., same or different flow rate, pressure, temperature, direction,etc.). The liquid anode channels can convey different liquid anodematerial or components. The liquid anodes can have differentcharacteristics (e.g., viscosity, corrosion, temperature conductivity,etc.). The multiple different liquid anodes can correspond to liquidanodes from the liquid anode table 700. In some embodiments, HEDAT-LAPchannel 821 can include a field's metal alloy, the HEDAT-LAP channel 822can include a wood's metal alloy, the HEDAT-LAP channel 823 can includea rose's metal alloy, and the HEDAT-LAP channel 821 can also include afield's metal alloy. It is appreciated that the material that forms thewalls or components of the different liquid anode channels can vary.

In some embodiments, the configuration of the channel flow areadimensions and the walls that form them are the same. In anotherembodiment, the configuration of the channel flow area dimensions andthe walls that form them vary. FIG. 9 is a block diagram of an exemplaryside view of HEDAT 800 with different channel dimensions. The side viewin FIG. 9 is through cut line AA of FIG. 8. The HEDAT-LAP channels(e.g., 821, 822, 823, 824, etc.) can have different dimensions. In someembodiments, the height and width dimensions of liquid anode channels821 and 824 are the same, the height dimensions of liquid anode channel822 and 823 are different than liquid anode channels 821 and 824, andthe width dimension of liquid anode channel 823 is different than liquidanode channels 821, 822, and 824. The walls (e.g., 871, 872, 873, 874,878, etc.) that form the HEDAT-LAP channels can have differentdimensions. In some embodiments, the height and width dimensions ofchannel walls 872 and 874 are the same, the height dimension of channelwall 873 is different than channel wall 872 and 874, and the widthdimension of channel walls 872 and 878 are different than 872 and 874.In some embodiments, a HEDAT-SAP (e.g., 871, 875, etc.) serve as channelwalls or surfaces. It is also appreciated that an interior HEDAT-LAPchannel wall (e.g., 872, 874, 877, 878, etc.) can include solid anodematerial and serve as both an anode and a channel wall.

FIG. 10 is an exemplary embodiment of another HEDAT-LAP 1000configuration. HEDAT-LAP 1000 includes liquid anode channels 1021, 1022,1023, and 1024 that are formed by channel walls 1011, 1012, 1013, 1014,and 1015. The shape of the channel walls 1011, 1012, 1013, 1014, and1015 can be different. The shape of the channel wall can be configuredto influence the liquid anode flow characteristics (e.g., increase ordecrease flow rate, pressure, density, etc.). The liquid anode flowcharacteristics can in turn influence various factors or characteristics(e.g., the radiation generation, the temperature dissipation, etc.).

In some embodiments, a HEDAT enables increased controllability andperformance over conventional liquid jet applications. The channel of aHEDAT-LAP confines a liquid anode to a more predictable behavior than anopen jet streaming in a less confined space. The density of the liquidanode can be less in input/output components than a HEDAT-LAP to enableease of flow to and from the liquid anode target. However, the flow canbe changed in the HEDAT-LAP. In one exemplary embodiment, channel walls1012 and 1013 can be utilized to impact the liquid anode flowcharacteristics (e.g., flow rate decreased, liquid compressed, densityincreased, etc.) to improve cooling and enable greater radiationgeneration. In some embodiments, the walls 1014 and 1015 are sloped tofacilitate drainage of a liquid anode from the HEDAT-LAP. The liquidanode can be drained (e.g., via drain 1033, etc.) when not in use toprevent or minimize set up or solidification of the liquid anode in theHEDAT.

It is appreciated that the flow in the channels can be configured andcontrolled separately. FIG. 11 is a block diagram of an exemplaryembodiment of HEDAT 1100. The HEDAT 1100 includes liquid anode channels1121, 1122, 1123, and 1124. The liquid anodes can flow in differentdirections in the liquid anode channels. The liquid anode flow in thechannels can have individual controls (e.g., valves 1131, 1132, 1133,etc.).

It is appreciated that the configuration of the input and outputcomponents can include channels and the configuration of the channelsand walls that form the channels can vary. In some embodiments, theconfiguration of the input and output components can include channelsand walls that are similar to the configuration of the channels andwalls within a HEDAT-LAP. In one exemplary implementation, a slip ringgantry is used and cooling liquid can be brought on and off the gantryvia pathways that include a rotary joint.

FIG. 12 is a block diagram of an exemplary radiation generation method1200.

In block 1210, an electron beam is received at a high energy dissipationanode target (HEDAT). In some embodiments, a high energy electron beamis received (e.g., greater than 1 MeV, etc.).

In block 1220, radiation is generated by collisions of the electron beamparticles in with components of the HEDAT. In some embodiments, theradiation is generated by collisions of the electron beam particles withboth a HEDAT-SAP and a HEDAT-LAP included in the high energy dissipationtarget. Energy resulting from electron beam collisions is absorbed bythe HEDAT-SAP and the HEDAT-LAP.

In block 1230, heat resulting from energy absorption in the HEDAT-SAPand the HEDAT-LAP is dissipated. In some embodiments, a portion of theheat generated in the solid anode is dissipated by a liquid anode flowin the HEDAT-LAP.

In block 1240, flow of a liquid anode material to and from the HEDAT-LAPis controlled. In some embodiments, the temperature of the liquid anodeis controlled.

In some embodiments, the flow rate is sufficiently high so that therequired beam power can be absorbed without causing a temperature risethat melts the walls of the chamber containing the anode materialitself, vaporize the anode material itself, or cause too high a densitychange. In an exemplary embodiment, Field's metal has density ofapproximately 7.9 gm/cc and a heat capacity of 285 J/kg. Thus, in orderto limit the temperature rise to +100 deg X, the flow rate should begreater than approximately 44.4 cc/s per kW delivered to a target. Todeliver 20 kW the flow rate should be about 88 cc/sec (approximately 6Tbsp/sec).

In some embodiments, a HEDAT is compatible with precisioncontrollability of the radiation beam. In some embodiments, a HEDATfacilitates generation and control of a relatively small diameter orcircumference radiation beam. In some embodiments, radiation generationcontrol facilitates ultra high radiation dose rates with high fidelitydelivery. The systems and methods can be compatible with pulse widthmodulation and timing control resolution is configured to facilitatedelivery fidelity approaching intra-pulse and micro-bunch levels (e.g.,corresponding to individual bunches per radio frequency cycle in a pulsewidth, etc.). The radio frequency can be in the microwave range. Thesystems and methods are also compatible with multiple field treatmentapproaches and can enable dose delivery for each fraction/field to beeffectively controlled. A HEDAT system can be implemented in systemsrunning at power levels greater than 1.5 kW.

It is appreciated that a high energy dissipation target (HEDT) has beendescribed with respect to a radiation generation target such as ananode. It is appreciated a HEDT can be utilized with various otherapplications in which a target is subjected to high energy beams. Insome embodiments, the HEDAT is included in a monitor component. Themonitor component can measure and track beam current and beam charge,which are used to draw a correlation with the dose rate and dose amountrespectively.

Thus, the presented systems and methods facilitate efficient andeffective radiation beam generation. In some embodiments, a HEDAT systemand method enables improved performance at higher energy levels overlimited traditional anode target approaches. The configuration selectionof the solid portion and liquid portion of the HEDAT enables changes andimprovements over conventional approaches, including operating at higherenergy, dissipating great heat emission, and so on. In some embodiments,X-ray fluences can be increased by at least an order of magnitude overconventional levels. In some embodiments, a radiation system including aHEDAT produces intrinsic beam fluences with comparable or betterspectral quality as those produced by a conventional slid only anodetarget. A HEDAT configuration can also facilitate better resolution anddecreased treatment spot sizes. In some embodiments, a radiation systemcomprising a HEDAT configuration facilitates small focal spots for newand current treatments. The HEDAT system configuration can facilitatesharper edge definition during treatment.

It is appreciated that HEDAT configurations can be utilized inapplications other that medical radiation applications. In someembodiments, HEDAT configurations can be utilized in variousapplications (e.g., medical, industrial, security, etc.). The HEDATconfiguration can facilitate improved (e.g., faster, better imageresolution, etc.) scanning of enclosed containers (e.g., packages,baggage, cargo scanning, etc.)

Some portions of the detailed descriptions are presented in terms ofprocedures, logic blocks, processing, and other symbolic representationsof operations on data bits within a computer memory. These descriptionsand representations are the means generally used by those skilled indata processing arts to effectively convey the substance of their workto others skilled in the art. A procedure, logic block, process, etc.,is here, and generally, conceived to be a self-consistent sequence ofsteps or instructions leading to a desired result. The steps includephysical manipulations of physical quantities. Usually, though notnecessarily, these quantities take the form of electrical, magnetic,optical, or quantum signals capable of being stored, transferred,combined, compared, and otherwise manipulated in a computer system. Ithas proven convenient at times, principally for reasons of common usage,to refer to these signals as bits, values, elements, symbols,characters, terms, numbers, or the like.

It should be borne in mind, however, that all of these and similar termsare associated with the appropriate physical quantities and are merelyconvenient labels applied to these quantities. Unless specificallystated otherwise as apparent from the following discussions, it isappreciated that throughout the present application, discussionsutilizing terms such as “processing”, “computing”, “calculating”,“determining”, “displaying” or the like, refer to the action andprocesses of a computer system, or similar processing device (e.g., anelectrical, optical or quantum computing device) that manipulates andtransforms data represented as physical (e.g., electronic) quantities.The terms refer to actions and processes of the processing devices thatmanipulate or transform physical quantities within a computer system'scomponent (e.g., registers, memories, other such information storage,transmission or display devices, etc.) into other data similarlyrepresented as physical quantities within other components.

The foregoing descriptions of specific embodiments of the presentinvention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteaching. The embodiments were chosen and described in order to bestexplain the principles of the invention and its practical application,to thereby enable others skilled in the art to best utilize theinvention and various embodiments with various modifications as suitedto the particular use contemplated. It is intended that the scope of theinvention be defined by the Claims appended hereto and theirequivalents. The listing of steps within method claims do not imply anyparticular order to performing the steps, unless explicitly stated inthe claim.

What is claimed:
 1. A therapeutic radiation generation systemcomprising: a particle beam gun that generates an electron beam; a highenergy dissipation anode target (HEDAT), configured to receive theelectron beam, absorb energy from the electron beam, generate aradiation beam, and dissipate heat, wherein the (HEDAT) includes aplurality of channels; and a liquid anode control component configuredto control a flow of a liquid anode to the HEDAT.
 2. The therapeuticradiation generation system of claim 1, wherein the plurality ofchannels are configured to accommodate a plurality of liquid anodeflows.
 3. The therapeutic radiation generation system of claim 2,wherein a first one of the plurality of channels is configured toaccommodate a first liquid anode flow and a second one of the pluralityof channels is configured to accommodate a second liquid anode flow. 4.The therapeutic radiation generation system of claim 2, wherein thefirst liquid anode flow and the second liquid anode flow are different.5. The therapeutic radiation generation system of claim 2, whereinconfiguration of a first one of the plurality of channels is differentthan configuration of a second one of the plurality of channels.
 6. Thetherapeutic radiation generation system of claim 2, wherein firstconfiguration of a wall in a first one of the plurality of channels isdifferent than a second configuration of a wall in a second one of theplurality of channels.
 7. The therapeutic radiation generation system ofclaim 6, wherein a difference in the first configuration of the firstone of the plurality of channels and the second configuration of thesecond one of the plurality of channels results in a difference of afirst flow of a liquid anode in the first one of the plurality ofchannels and a second flow of a liquid anode.
 8. The therapeuticradiation generation system of claim 2, wherein a first configuration ofthe first one of the plurality of channels and a second configuration ofthe second one of the plurality of channels are coordinated for impactson radiation emission from the HEDAT.
 9. The therapeutic radiationgeneration system of claim 1, wherein a first one of the plurality ofchannels includes a first liquid anode and a second one of the pluralityof channels includes a second liquid anode, wherein the first liquidanode is different than the second liquid anode.
 10. A radiation methodcomprising: receiving an electron beam at a high energy dissipationanode target (HEDAT); absorbing energy from collisions of the electronbeam with a wall of a channel and collisions of the electron beam withliquid anode contents in a plurality of channels in the HEDAT;generating radiation based upon the energy absorption; and dissipatingheat resulting from energy absorption.
 11. The radiation method of claim10, further comprising: controlling flow of a first liquid anode througha first one of the plurality of channels; and controlling flow of asecond liquid anode through a second one of the plurality of channels.12. The radiation method of claim 10, further comprising forwarding aradiation beam to a treatment target.
 13. The radiation method of claim12, further comprising controlling liquid anode flows in the respectiveplurality of channels.
 14. The radiation method of claim 13, whereincontrolling the liquid anode flows includes adjusting the liquid anodeflows based on resulting impacts to characteristics of the radiationbeam.
 15. A radiation therapy system comprising: a beam generationsystem that generates and transports a radiation beam in accordance witha prescribed treatment plan, where the beam generation system includes:a particle beam gun that generates a particle beam; a high energydissipation anode target (HEDAT), configured to receive the electronbeam, absorb energy from the electron beam, generate a radiation beam,and dissipate heat, wherein the (HEDAT) includes a channel configured toaccommodate a liquid anode and a portion of a wall of the channelincludes a solid anode; and a liquid anode control component configuredto control a flow of the liquid anode.
 16. The radiation therapy systemof claim 15, wherein walls of the channel are configured to causecompress of the liquid anode in a manner that contributes to increasedradiation emission.
 17. The radiation therapy system of claim 15,wherein walls of the channel are configured to maintain a flow patternand reduce local recirculation eddies.
 18. The radiation therapy systemof claim 15, wherein walls of the channel are configured to impact theflow of the liquid anode.
 19. The radiation therapy system of claim 15,wherein the channel includes a solid anode portion (HEDAT-SAP) and aliquid anode portion (HEDAT-LAP).
 20. The radiation therapy system ofclaim 15, wherein the HEDAT-SAP and HEDAT-LAP cooperatively operate toenhance energy compatibility characteristics of the HEDAT.